Power bank



FIG. 1 is a front perspective view of a power bank showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings are for the purpose of illustrating portions of the power bank which form no part of the claimed design.

The portions including surface shading represent contour and not surface ornamentation. 

CLAIM The ornamental design for a power bank, as shown and described. 